fold — Adds artificial foldover to an audio signal.
asig -- input signal
kincr -- amount of foldover expressed in multiple of sampling rate. Must be >= 1
fold is an opcode which creates artificial foldover. For example, when kincr is equal to 1 with sr=44100, no foldover is added. When kincr is set to 2, the foldover is equivalent to a downsampling to 22050, when it is set to 4, to 11025 etc. Fractional values of kincr are possible, allowing a continuous variation of foldover amount. This can be used for a wide range of special effects.
Here is an example of the fold opcode. It uses the file fold.csd.
Example 155. Example of the fold opcode.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform ; Audio out Audio in No messages -odac -iadc -d ;;;RT audio I/O ; For Non-realtime ouput leave only the line below: ; -o fold.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> ; Initialize the global variables. sr = 44100 kr = 4410 ksmps = 10 nchnls = 1 ; Instrument #1. instr 1 ; Use an ordinary sine wave. asig oscils 30000, 100, 1 ; Vary the fold-over amount from 1 to 200. kincr line 1, p3, 200 a1 fold asig, kincr out a1 endin </CsInstruments> <CsScore> ; Play Instrument #1 for four seconds. i 1 0 4 e </CsScore> </CsoundSynthesizer>